Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:LCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-6757 is a medium-severity Access of Uninitialized Pointer (CWE-824) vulnerability in Mozilla Firefox. Its CVSS base score is 6.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Steganography (T1001.002); ranked at the 19th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-6757 is an invalid pointer vulnerability (CWE-824) in the JavaScript WebAssembly component of Mozilla products. It affects Firefox versions prior to 150, Firefox ESR prior to 140.10, Thunderbird prior to 150, and Thunderbird prior to 140.10. The issue stems from an access of an uninitialized pointer, which can lead to memory corruption when processing malicious WebAssembly content.
The vulnerability has a CVSS v3.1 base score of 6.3 (AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L), indicating that an unauthenticated remote attacker can exploit it over the network with low complexity but requires user interaction, such as visiting a malicious website or opening a crafted email in Thunderbird. Successful exploitation could result in limited impacts, including disclosure of sensitive information, minor modification of data, or partial denial of service due to application crashes or corruption.
Mozilla security advisories (MFSA 2026-30 through 2026-34) and the associated Bugzilla entry (bug 2013588) confirm the issue was addressed in the listed fixed releases. Security practitioners should prioritize updating affected Firefox and Thunderbird installations to mitigate the risk, as no workarounds are specified in the provided references.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-24098
Vulnerability Data
Invalid pointer in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover uninitialized pointer accesses through static analysis, dynamic testing, or fuzzing before deployment.
Requiring documented development processes and tools enables use of analyzers or coding standards that identify uninitialized pointer defects.
Security engineering principles can mandate memory-safety practices and language choices that structurally avoid uninitialized pointer use.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly prevent uninitialized pointer bugs via coding standards, analysis, and reviews, but eliminating this single weakness only partially fulfills the broader control.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.